From c8c2bb6784d70cdc6e3a75a24fc9d09970a574e4 Mon Sep 17 00:00:00 2001
From: Vladimir Marko <vmarko@google.com>
Date: Fri, 15 Oct 2021 09:33:09 +0100
Subject: JNI compiler: Rewrite exception polling.

Make the slow path explicit in the JNI compiler. Fix the
CFI data for the exceptional path of synchronized methods.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Test: run-gtests.sh
Test: testrunner.py --target --optimizing
Bug: 172332525
Change-Id: If64965eef15c063e36b78dd8bb6cba5af34ab4fa
---
 compiler/jni/quick/jni_compiler.cc | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

(limited to 'compiler/jni/quick/jni_compiler.cc')

diff --git a/compiler/jni/quick/jni_compiler.cc b/compiler/jni/quick/jni_compiler.cc
index 25eb919c53..5752c7562a 100644
--- a/compiler/jni/quick/jni_compiler.cc
+++ b/compiler/jni/quick/jni_compiler.cc
@@ -288,6 +288,8 @@ static JniCompiledMethod ArtJniCompileMethodInternal(const CompilerOptions& comp
   // 5. Call into appropriate JniMethodStart passing Thread* so that transition out of Runnable
   //    can occur. We abuse the JNI calling convention here, that is guaranteed to support passing
   //    two pointer arguments.
+  std::unique_ptr<JNIMacroLabel> monitor_enter_exception_slow_path =
+      UNLIKELY(is_synchronized) ? __ CreateLabel() : nullptr;
   if (LIKELY(!is_critical_native)) {
     // Skip this for @CriticalNative methods. They do not call JniMethodStart.
     ThreadOffset<kPointerSize> jni_start =
@@ -328,7 +330,7 @@ static JniCompiledMethod ArtJniCompileMethodInternal(const CompilerOptions& comp
     }
     method_register = ManagedRegister::NoRegister();  // Method register is clobbered.
     if (is_synchronized) {  // Check for exceptions from monitor enter.
-      __ ExceptionPoll(main_out_arg_size);
+      __ ExceptionPoll(monitor_enter_exception_slow_path.get());
     }
   }
 
@@ -602,8 +604,10 @@ static JniCompiledMethod ArtJniCompileMethodInternal(const CompilerOptions& comp
 
   // 17. Process pending exceptions from JNI call or monitor exit.
   //     @CriticalNative methods do not need exception poll in the stub.
+  std::unique_ptr<JNIMacroLabel> exception_slow_path =
+      LIKELY(!is_critical_native) ? __ CreateLabel() : nullptr;
   if (LIKELY(!is_critical_native)) {
-    __ ExceptionPoll(/* stack_adjust= */ 0);
+    __ ExceptionPoll(exception_slow_path.get());
   }
 
   // 18. Remove activation - need to restore callee save registers since the GC may have changed
@@ -673,7 +677,21 @@ static JniCompiledMethod ArtJniCompileMethodInternal(const CompilerOptions& comp
     }
   }
 
-  // 20. Finalize code generation
+  // 20. Emit exception poll slow paths.
+  if (LIKELY(!is_critical_native)) {
+    if (UNLIKELY(is_synchronized)) {
+      __ Bind(monitor_enter_exception_slow_path.get());
+      if (main_out_arg_size != 0) {
+        jni_asm->cfi().AdjustCFAOffset(main_out_arg_size);
+        __ DecreaseFrameSize(main_out_arg_size);
+      }
+    }
+    DCHECK_EQ(jni_asm->cfi().GetCurrentCFAOffset(), static_cast<int>(current_frame_size));
+    __ Bind(exception_slow_path.get());
+    __ DeliverPendingException();
+  }
+
+  // 21. Finalize code generation
   __ FinalizeCode();
   size_t cs = __ CodeSize();
   std::vector<uint8_t> managed_code(cs);
-- 
cgit v1.2.3-59-g8ed1b